Outline of Electronic Fuel Injection and Idle Speed Control System


EFI (Electronic Fuel Injection)System
The EFI system uses various sensors to detect the operating conditions of the engine and the vehicle. In accordance with the signals from these sensors, the ECU calculates the optimal fuel injection volume and operates the injectors in order to inject the proper volume of fuel. During ordinary driving, the engine ECU determines the fuel injection volume for achieving the theoretical air-fuel ratio, in order to ensure the proper power, fuel consumption, and exhaust emission levels simultaneously. At other times, such as during warm-up, acceleration, deceleration, or high-load driving conditions, the engine ECU detect those conditions with the various sensors and then corrects the fuel injection volume in order to ensure an optimal air-fuel mixture at all times. (1/1)
ESA (Electronic Spark Advance) System
The ESA system detects the conditions of the engine based on the signals provided by various sensors, and controls the spark plugs to generate sparks at the appropriate timing. Based on engine speed and engine load, the ESA precisely controls the ignition timing so that the engine can generate improve power, purify exhaust gases, and prevent knocking in an effective manner.
ISC (Idle Speed Control) System
The ISC system controls the idle speed so that it is always appropriate under varying conditions (warm-up, electrical load, etc.). To minimize fuel consumption and noise, an engine must operate at a speed that is as low as possible while maintaining a stable idle. Moreover, the idle speed must be increased to ensure the proper warm-up and drivability when the engine is cold or the air conditioner is being used.
Diagnostic System
The engine ECU contains a diagnostic system. The ECU constantly monitors the signals that are being input by various sensors. If it detects a malfunction with an input signal, the ECU records the malfunction in the form of DTCs (Diagnostic Trouble Codes) and illuminates the MIL (Malfunction Indicator Lamp). If necessary, the ECU can output the DTCs by blinking the MIL or displaying the DTCs or other data on the display panel of a handheld tester. The diagnostic functions that output the DTCs and datas of a malfunction on a hand-held tester are a highly advanced and complex form of electronics system. Because a diagnostic system must comply with the regulations of each country, its contents vary slightly by destination.

Related Post